I know a guy that tells me he loves me but continues off and on to have this "thing" with someone else, she?

comes to his house to help him with outside work, now helping him with building the walls of his garage, vacuums, whatever and then she wants to have with him even if he does not reciprocate back, i am sure you know what i mean, then he will tell me that he just wants to be friends with her and the minute i am unhappy about her or anything else he goes right back to allowing her to....i amm sick of it, him telling me he loves me, he even says he will ask for a shrink at the v.a. i really don't think he will ever change, will he?